BOTH INTERNATIONAL & INLAND The tow shown in illustration D024RR below is less than 200 meters in length and severely restricted in her ability to deviate from her course. Which shape(s) would be displayed by day from the vessel(s)?

Correct Answer: Option C — ball-diamond-ball on the towing vessel

Rule 27(b) requires vessels restricted in their ability to maneuver to display three shapes in a vertical line: a ball, a diamond, and a ball. This signal indicates the vessel is constrained by the nature of her work, such as a tug with a tow, and requires other vessels to stay clear.